Communication equipment requires various frequency bands when operating. To this end, the communication equipment must include devices for generating and processing (amplifying) frequencies. The devices for generating and processing (amplifying) frequencies may be realized by using crystal and LC resonance circuits.
The frequencies generated by the LC resonance circuit vary depending on an inductor L and a capacitor C. Therefore, various frequencies may be generated by adjusting the inductor L and the capacitor C in the LC resonance circuit. In most of cases, the frequencies are changed by adjusting the capacitor C in the LC resonance circuit.
Therefore, researches and studies on a scheme of continuously or discretely varying a capacitance by using micro electro mechanical systems (MEMS) have been variously performed. In particular, researches and studies of varying the capacitance and the inductance through the continuous mechanical displacement of a driving unit of the MEMS have been performed.